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Message-ID: <tencent_DABB2333139E8D1BCF4B5D1B2725FABA9108@qq.com>
From: Edward Adam Davis <eadavis@qq.com>
To: syzbot+2c4a3b922a860084cc7f@syzkaller.appspotmail.com
Cc: adilger.kernel@dilger.ca,
	linux-ext4@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com,
	tytso@mit.edu
Subject: [PATCH] ext4: fix WARNING in lock_two_nondirectories
Date: Sun, 24 Dec 2023 19:53:00 +0800
In-Reply-To: <000000000000e17185060c8caaad@google.com>
References: <000000000000e17185060c8caaad@google.com>
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If inode is the ext4 boot loader inode, then when it is a directory, the inode
should also be set to bad inode.

Reported-and-tested-by: syzbot+2c4a3b922a860084cc7f@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 fs/ext4/inode.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 61277f7f8722..b311f610f008 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4944,8 +4944,12 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
 		inode->i_fop = &ext4_file_operations;
 		ext4_set_aops(inode);
 	} else if (S_ISDIR(inode->i_mode)) {
-		inode->i_op = &ext4_dir_inode_operations;
-		inode->i_fop = &ext4_dir_operations;
+		if (ino == EXT4_BOOT_LOADER_INO)
+			make_bad_inode(inode);
+		else {
+			inode->i_op = &ext4_dir_inode_operations;
+			inode->i_fop = &ext4_dir_operations;
+		}
 	} else if (S_ISLNK(inode->i_mode)) {
 		/* VFS does not allow setting these so must be corruption */
 		if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
-- 
2.43.0